SEVERE: Exception starting filter struts2
java.lang.NoClassDefFoundError: IllegalName: com/ruibo/action/Test1
    at java.lang.ClassLoader.preDefineClass(ClassLoader.java:646)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:785)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2944)
    at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1208)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1688)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1569)
    at com.opensymphony.xwork2.util.ClassLoaderUtil.loadClass(ClassLoaderUtil.java:144)
    at com.opensymphony.xwork2.ObjectFactory.getClassInstance(ObjectFactory.java:108)
    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.verifyAction(XmlConfigurationProvider.java:470)
    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.addAction(XmlConfigurationProvider.java:424)
    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.addPackage(XmlConfigurationProvider.java:541)
    at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadPackages(XmlConfigurationProvider.java:290)
    at org.apache.struts2.config.StrutsXmlConfigurationProvider.loadPackages(StrutsXmlConfigurationProvider.java:112)
    at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:239)
    at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:68)
    at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:429)
    at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:471)
    at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:74)
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.init(StrutsPrepareAndExecuteFilter.java:51)
    at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:279)
    at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:260)
    at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:105)
    at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4809)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5485)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:632)
    at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1229)
    at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1875)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
    at java.util.concurrent.FutureTask.run(FutureTask.java:166)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:722)

五月 30, 2015 11:30:39 上午 org.apache.catalina.core.StandardContext startInternal
SEVERE: Error filterStart
五月 30, 2015 11:30:39 上午 org.apache.catalina.core.StandardContext startInternal
SEVERE: Context [/struts2_demo1] startup failed due to previous errors
五月 30, 2015 11:30:39 上午 org.apache.coyote.AbstractProtocol start

没有找到相应的类……1.你看你用struts2 框架时候是不是配置文件错了2.还有就是你的jar包有没有全部导进去，缺少框架的相关jar包也是会错的……

好好看看jar包，之后是web.xml文件。自己导jar包就总会出这种问题